def adjust_ip(self, ip=None):
"""Called to explicitely fixup an associated IP header
The function adjusts the IP header based on conformance rules
and the group address encoded in the IGMP message.
The rules are:
1. Send General Group Query to 224.0.0.1 (all systems)
2. Send Leave Group to 224.0.0.2 (all routers)
3a.Otherwise send the packet to the group address
3b.Send reports/joins to the group address
4. ttl = 1 (RFC 2236, section 2)
5. send the packet with the router alert IP option (RFC 2236, section 2)
"""
if ip != None and ip.haslayer(IP):
if (self.type == 0x11):
if (self.gaddr == "0.0.0.0"):
ip.dst = "224.0.0.1" # IP rule 1
retCode = True
elif isValidMCAddr(self.gaddr):
ip.dst = self.gaddr # IP rule 3a
retCode = True
else:
print "Warning: Using invalid Group Address"
retCode = False
elif ((self.type == 0x17) and isValidMCAddr(self.gaddr)):
ip.dst = "224.0.0.2" # IP rule 2
retCode = True
elif ((self.type == 0x12) or
(self.type == 0x16)) and (isValidMCAddr(self.gaddr)):
ip.dst = self.gaddr # IP rule 3b
retCode = True
else:
print "Warning: Using invalid IGMP Type"
retCode = False
else:
print "Warning: No IGMP Group Address set"
retCode = False
if retCode == True:
ip.ttl = 1 # IP Rule 4
ip.options = [IPOption_Router_Alert()] # IP rule 5
return retCode
def adjust_ip (self, ip=None):
"""Called to explicitly fixup an associated IP header
The function adjusts the IP header based on conformance rules
and the group address encoded in the IGMP message.
The rules are:
1. Send General Group Query to 224.0.0.1 (all systems)
2. Send Leave Group to 224.0.0.2 (all routers)
3a.Otherwise send the packet to the group address
3b.Send reports/joins to the group address
4. ttl = 1 (RFC 2236, section 2)
5. send the packet with the router alert IP option (RFC 2236, section 2)
"""
if ip != None and ip.haslayer(IP):
if (self.type == 0x11):
if (self.gaddr == "0.0.0.0"):
ip.dst = "224.0.0.1" # IP rule 1
retCode = True
elif isValidMCAddr(self.gaddr):
ip.dst = self.gaddr # IP rule 3a
retCode = True
else:
print "Warning: Using invalid Group Address"
retCode = False
elif ((self.type == 0x17) and isValidMCAddr(self.gaddr)):
ip.dst = "224.0.0.2" # IP rule 2
retCode = True
elif ((self.type == 0x12) or (self.type == 0x16)) and (isValidMCAddr(self.gaddr)):
ip.dst = self.gaddr # IP rule 3b
retCode = True
else:
print "Warning: Using invalid IGMP Type"
retCode = False
else:
print "Warning: No IGMP Group Address set"
retCode = False
if retCode == True:
ip.ttl=1 # IP Rule 4
ip.options=[IPOption_Router_Alert()] # IP rule 5
return retCode